Th-42Pd25U Sc And Ss Sos Detect - Panasonic GP6DU Technical Manual

TH-42PD25U SC and SS SOS Detect

The Scan and Sustain voltages on the SC and SS boards are monitored in a similar
manner. The +15V Line on the SS board is fed to a voltage divider and the result is
compared to a reference voltage. The reference voltage is provided by a zener diode. If
the output of the comparator goes high, a transistor turns on, effectively grounding the
SOS line. The SC board uses a similar circuit.
Additionally, the SS and SC boards contain LED indicators to alert the technician when
a problem exists. The LED should be lit during normal operation, a dark LED indicates
that a problem exists on that board.
Figure 30 - SC board SOS Detect
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